All tracks of a line should be counted which run mostly parallel, are connected by switches on both ends or have several passenger stations on their way. Values can be 1 or more, i.e., 2 for a double-track railway. In this case it says that there is one other track belonging to the same railway line, even if it is not all the way running exactly parallel. The counting of tracks should be like it is recognised by the general public and be consistent all over the world. If for example the media refers to a project of improving a double track to a four track railway there should be found passenger_lines=2 before and passenger_lines=4 after the construction work. The counting should not follow internal regulations of specific or national railway companies.

Naming

Despite the "passenger" in the name all kinds of tracks connecting the same railway stations or junction should be counted with no regard to the train services running on it. The kind of train service should be tagged with railway:traffic_mode=*. So it is some kind of workaround, since tracks=* or lanes=* are not to be used for this topic. The reason of the naming is that this tag was first used in an area where lines for goods or freight traffic are very rare. Better ideas were line_tracks=* or running_lines=*. But it seemed better to use the already completed work than starting with a completely new tag.